Heat-transmitting tube of steam generators



oct. 12 1926.

Z. J. H. JONKER HEAT TRANSMITTING TUBE oF STEAM GENERAToRs Filed O t. 16, 1924 BOILEFZ CHAMBER.

m B M A H. rb A N R U F Patented Oct. 12, 1926.

UNITED STATES PATENT yo1= 1'-1ca.1

ZEGEBYJAN HENDRIK J ONKER, VOIF HILVERSUM, NETHERLANDS.

HEAT-TRANSMITTING TUBE F STEAM GENERATORS.,

Application led October 16, 1924, Serial No. 743,933, and in Netherlands November 30, 1923.

The present invention relates to improvements in or modifications of the improved heat transmitting tubes of steam generators as set forth in the American application Ser.

No. 599,870 filed November 9, 1922.

In accordance with the invention the improvements chiefly consist in that the return tube which leads into the main tube within the boiler space through an opening in the lower end thereof, is prolonged down to the bottom and is arranged concentrically within said main tube, whilst the lowermost extremity of the return tube is closed and is provided with holes in it.

This improved construction in use has the advantage that when the lire comes in 'contact with the main tubes, whereby the 'formation of steam through radiation from a large tube surface is considerably increased, no risk of dryness of the main tube and consequent explosion thereof need be feared.

An example of construction of the invention is shown in the accompanying drawing, being a part sectional elevation through a main tube with return tube.

The boiler with its bottomkplate 1 and furnace 2 contains a plurality of sealed tubes which are secured to the bottom plate 1 of the boiler by means of a threaded ferrule 7. The lower portion 3 of the tube projects into the furnace whilst the upper portion 4 is disposed in the interior of the boiler, The return tube 6 which branches off the head of the main tube and runs along it,

leads into the main tube inthe lower part of the boiler and runs concentrically with-` in it to the bottom thereof.

The return tube is closed at its lowermost extremity but is provided, however, with holes 8 arranged around it. In order to increase the conduction of heat to the boiler water, the portions of the tubes projecting within the boiler are provided with fins 9.

The action is as follows:

The flames of the iire contact with those parts of the tubes disposed within the furnace whilst these parts are also heated by radiation from the furnace. The liquid contained in the sealed tubes is evaporated, steam rising in that portion of the tube which is disposed within the boiler and Ytransmitting tube having its lower end located in said furnace chamber and its upper portion in said boiler chamber; and a return tube for the Water of condensation leading from the upper end of said heat-transmitting tube. outside the upper portion of the latter to the lower portion thereof, and passing through the outer wall of said heattransmitting tube in the lower end ofsaid boiler chamber and extending therebeyond within the lower end portion of said heat` transmitting tube in the furnace chamber, the lower end of said return tube being closed and the lateral wall of said return- Vtube being apertured above said closed lower end.

2. In an apparatus of the class described, a furnace chamber; a boiler chamber; means separating said chambers; a sealed heattransmittingtube having its lower end located in said furnace chamber and its upper portion in said boiler chamber; a return tube for the water of condensation leading from the upper end of said heat-transmitting tube outside the upper portion ofthe latter to the lower portion thereof and passing through the outer wall of said heat-v transmitting tube in the lower end of said boiler chamber and extending therebeyond within the lower end portion of said heattransmitting tube in the furnace chamber, the lower end of said return tube being closed and the lateral wall of said return tube' being apertured above said closed lower end, and a plurality of longitudinal ribs about said heat-transmitting tube Within said boiler chamber.

3. In an apparatus of the class described, the combination of means presenting a furw nace chamber; a boiler chamber; a Wall said separating Wall, and thence to a point separating said chambers; u sealed heatbelow said separating Wall, the lower end of 143 transmitting tub-e extending through said said return tube being closed, and the lateral Wall; and u condensation return tube lead- Wall of Said return tube above said closed 'ing from the upper portion of said lieatend being aperturefl.

transmitting` tube, irst externally of, thence In testimony whereof, I have signed my through the lateral Wall of said transmitting nnie to this Specification.

tube to the interior of the latter Iabove J. H: JONKER. 

